Description:
------------
Testing against the latest PHP 7 version, there seem to be a bug with the strtr function. As soon as you use replace pairs (the 2 arguments usage), the function won't replace anything if the replace pairs are matching eachother (e.g. in the test script "foobar" matches both "fo" and "bar").

From some tests[1], it seems like this bug has been introduced between January 1st and February 1st in the PHP 7 branch.

 [1] http://3v4l.org/FTV2L

Test script:
---------------
<?php
$tests = array('bar' => '', 'foo' => 'o', 'foobar' => '', 'hello' => 'hello');

foreach ($tests as $input => $expected) {
    if ($expected !== ($actual = strtr($input, array("fo" => "", "foobar" => "", "bar" => "")))) {
        echo "KO `$input` became `$actual` instead of `$expected`\n";
    } else {
        echo "OK `$input` became `$expected`\n";
    }
}
?>

Expected result:
----------------
OK `bar` became ``
OK `foo` became `o`
OK `foobar` became ``
OK `hello` became `hello`

Actual result:
--------------
KO `bar` became `bar` instead of ``
KO `foo` became `foo` instead of `o`
KO `foobar` became `foobar` instead of ``
OK `hello` became `hello`